This invention relates to drip irrigation, and more particularly to a drip irrigation hose with pressure compensation and a method for its manufacture.
Drip irrigation hose can be classified as having either discrete emitters or continuous integral emitters. An example of discrete emitters is shown in U.S. Pat. No. 4,850,531. An example of continuous integral laminar flow emitters is shown in U.S. Pat. No. 4,247,051.
A design objective of drip irrigation hose is uniformity of the drip rate from each emitter. Since the water pressure in a drip irrigation system varies as a function of elevation of the field, it is customary to incorporate a pressure regulating mechanism into the emitters. Turbulent flow rate is less sensitive to pressure variation than laminar flow rate. Accordingly, it has been common practice for drip irrigation hose to employ serpentine flow regulating passages as continuous integral emitters to promote turbulent flow. An example of such drip irrigation hose is disclosed in U.S. Pat. No. 4,984,739.